| 摘要: |
| 消化酶活力能够反映刺参对不同营养成分的消化能力。当某一反应条件发生改变时,消化酶的活力大小就会发生变化,因此研究不同因子对消化酶活力的影响对于了解消化酶的性质具有重要的意义。温度和pH是影响消化酶活力的最重要的反应条件。本文中作者应用酶学分析研究了温度和pH对剌参前肠和中肠各种消化酶活力的影响。蛋白酶活力测定采用福林-酚法,脂肪酶活力测定采用水解法,淀粉酶活力和纤维素酶活力测定采用水杨酸显色法。实验结果表明,反应温度和反应pH对刺参前肠和中肠中的消化酶活力具有显著影响(P<0.05)。前肠和中肠中蛋白酶活力均在反应温度为50°C时达到最大值,前肠和中肠中脂肪酶和纤维素酶均在反应温度为40°C时达到最大值,而前肠和中肠中淀粉酶最适反应温度分别为40°C和30°C。刺参前肠蛋白酶活力在酸性环境下较中肠高,且在反应pH为5.0-5.8之间酶活力相对稳定,而中肠蛋白酶活力在碱性环境下较前肠高,且在反应pH为7.0-8.6之间酶活力相对稳定;刺参前肠脂肪酶活力随着pH的升高出现两个相对稳定的峰值,分别为4.2-5.0和6.2-7.0区间,中肠脂肪酶活力在pH为3.8时达到最大值,而在pH超过9.0明显失活；刺参前肠和中肠淀粉酶活力在pH变化时表现出相似的变化趋势，在反应pH为6.6-7.4之间酶活力较高且相对稳定；刺参前肠和中肠种纤维素酶活力在pH变化时反应一致，前肠淀粉酶在反应pH为6.2-7.4之间酶活力较高且相对稳定，中肠纤维素酶活力在反应pH为5.4-7.0之间酶活力较高且相对稳定。此外，通过比较四种消化酶活力值的大小，可以看出刺参蛋白酶活力较高，其次为纤维素酶和淀粉酶活力，而脂肪酶活力最低。 |
| 关键词: 刺参 温度 pH 消化酶 |
| DOI： |
| 分类号: |
| 基金项目:山东省优秀中青年科学家科研奖励基金资助项目,2006BS08012号;青岛自然科学基金资助,05-1-JC-87号 |
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| EFFECTS OF TEMPERATURE AND pH ON THE ACTIVITIES OF DIGESTIVE ENZYMES IN APOSTICHOPUS JAPONICUS |
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JIANG Ling-Xu, YANG Ning, LI Jian, WANG Wen-Qi, WANG Ren-Jie, Lu Jie
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Qingdao Agricultural University,Aquaculture College,Qingdao,266109
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| Abstract: |
| Activities of digestive enzyme reflect the digestive level of Apostichopus japonicus to different nutritional ingredients. Any changes in ambient factors would affect the activity of a digestive enzyme. Studying different ambient factors on the digestive enzymes in the A. japonicas is important for understanding the behavior of the enzymes. Among ambient factors. temperature and pH are the most two important affecting factors. Enzyme activities were analyzed including protease, lipase, amylase, and cellulase by Folin-phenol method, turbidimetric method, and colorimetric assay of salicylic acid. The results showed that temperature and pH had notable effects on the activities of digestive enzymes in foregut and midgut of Apostichopus japonicus (P < 0.05). The optimum temperature of protease, lipase, and cellulase was 50°C, 40°C, and 40°C, respectively in both foregut and midgut. while the optimum temperature of amylase was 40°C in foregut and 30°C in midgut. The protease activity in foregut was higher than that of midgut in an acidic condition at pH 5.0 - 5.8, while in an alkalescence condition at pH 7.0 - 8.6. The protease activity was higher in midgut than that in foregut. The lipase activity of foregut was high and stable in two pH ranges: 4.2 - 5.0 and 6.2 - 7.0, and that of midgut was high at pH 3.8, while the lipase lost enzyme activity at pH over 9.0. The amylase activity was high and stable at pH 6.6 - 7.4 in both foregut and midgut. The cellulase activity of foregut and midgut was high and stable at pH 6.2 - 7.4 and 5.4 - 7.0 respectively. Therefore, the protease activity was the highest among all digestive enzymes, followed by cellulase and amylase activities, and the lipase activity was the lowest. |
| Key words: Apostichopus japonicus, Temperature, pH, Digestive enzyme |
